Surveying system and auxiliary measuring instrument

ABSTRACT

A method comprising: setting up a stationary surveying device at a first known positioning in a surrounding area of the object; retrieving from a memory a set of object points of an object to be surveyed and/or to be marked; surveying and/or marking from a first positioning object points of the set of object points that can be surveyed and/or can be marked from the first positioning by means of the free beam, on the basis of a target direction; ascertaining missing object points of a set of object points; relocating the surveying device to a second, unknown positioning in the surrounding area of the object; automatically determining a second positioning by the surveying device on the basis of the knowledge of the first positioning, so that the second positioning is known; surveying and/or marking missing object points by means of the free beam from the second positioning.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/290,218, filed on Oct. 31, 2018; which is a National Stage Entry ofPCT/EP2018/079910, filed on Oct. 31, 2018. The foregoing patentapplications are herein incorporated by reference.

FIELD OF THE INVENTION

The invention relates to an auxiliary measuring instrument, a surveyingsystem or surveying device and a position-determining or marking method.

BACKGROUND

Surveying systems for determining positions in the field of geodesy orthe area of construction sites and/or construction are known in manifoldforms. Examples of these are systems made up of a stationary surveyingdevice with a direction and range meter, such as for example a totalstation, and an auxiliary measuring instrument marking a point to besurveyed or identified, such as for example a plumbing pole. Also knownare layout systems made up of a stationary laser emitter, which by meansof a laser beam generates a position reference, which can be received bya laser receiver at the point to be marked. Surveying activities arethus performed by the interaction of a stationary device at a knownlocation, which thus offers a position reference, with a receiving ormarking and/or targetable measuring aid, whereby the position ofindividual terrain points such as land surveying points or points onconstruction site objects, for example in the interior or exterior areaof buildings or in road construction, can be determined precisely withrespect to position measurement or stake out.

BRIEF SUMMARY

The object of the present invention is to provide an improved surveyingsystem or improved system device and improved surveying method.

This object is achieved by the implementation of the characterizingfeatures of the independent claims. Features which refine the inventionin an alternative or advantageous manner can be inferred from thedependent patent claims and the description, including the descriptionsof the figures. All of the embodiments that are shown or otherwisedisclosed in this document can be combined with one another unlessotherwise expressly stated.

A first aspect relates to an auxiliary measuring instrument, inparticular a surveying pole or plumbing pole, which is designed to formtogether with a ground-based, in particular stationary, surveying devicehaving range-and-direction measuring functionality, in particular atotal station, a system for surveying and/or staking out terrain points.“Terrain point” should be understood here in a broad sense and comprisesfor example not only points on open or free terrain, but also points ofor on buildings or construction sites, both in the interior area andexterior area. The auxiliary measuring instrument has a handheld mainbody with a defined longitudinal axis, so that the auxiliary measuringinstrument can be used as a handy means for aiming at a terrain point.The auxiliary measuring instrument is designed for example as a pole,the one end of which can be positioned on the terrain point. Solutionsin which the point is not aimed at physically, but for example by themeasuring beam of a distance meter, are also known from the prior artand included here. In any event, a distance from a, in particularreference point of the main body to the terrain point is predefined orgiven or can be determined by the auxiliary measuring instrument itself.

Furthermore, the auxiliary measuring instrument has a target, which isattached to the main body in a defined and known spatial relationshipwith the longitudinal axis and with the reference point and the positionof which can be determined by the surveying device, so that, bytargeting at the terrain point with the measuring instrument, a targetposition linked with the terrain point can be displayed.

Furthermore, the auxiliary measuring instrument has on the main body, ina defined and known spatial relationship with the longitudinal axis, anattached body, preferably a sphere attachment, in particular wherein thecenter of the body is arranged on the longitudinal axis. The body bearson its surface a two-dimensional code, which can be bijectivelyevaluated by image processing, so that an orientation of the attachment,and consequently (with knowledge of the defined and known relationship)the orientation (roll, pitch and yaw angles) of the auxiliary measuringinstrument can be determined.

Optionally, the code is designed and distributed over the surface of thebody in such a way that the orientation of the auxiliary measuringinstrument can be bijectively determined on the basis of a segment ofthe surface of the body, and consequently the code, recorded in a cameraimage.

As a further option, the code has at least a first and second resolutionstage, wherein the first resolution stage is designed for imagerecording and code evaluation in the near range and the secondresolution stage is designed for image recording and code evaluation inthe far range and/or the first resolution stage serves for coarseinclination and orientation determination and the second resolutionstage serves for fine inclination and orientation determination. Forexample, the code has precisely three resolution stages.

In a further development, the code is arranged in two parts on thesurface of the sphere, in that a first part serves for coding a firstdirection on the surface of the sphere, in particular the length or thelongitude, and a second part serves for coding a second direction, inparticular the width or the latitude, in particular wherein the firstpart and the second part are of different colors, for example red andgreen. Color is understood here as also meaning colors that lie outsidethe visible range, for example in the near IR spectrum or in the UVrange.

Optionally, the target is integrated in the sphere attachment, forexample in that the surface of the sphere has a multiplicity ofretroreflectors which can be aimed at by the surveying device. As afurther option, the auxiliary measuring instrument has a light source,with which the surface of the sphere can be illuminated, in particularwherein the light source is arranged in the interior of the sphereattachment. As a further option, the light source can be activated insuch a way that, by varying the illumination, for example changing thecolor and/or intensity (for example flashing), a transmission ofinformation is made possible, for example to the surveying device. Thus,for example, the current status of the surveying device, for example thereadiness for use or an ID, can be communicated by means of a lightsignal or instructions to a user can be given on the surveying device.

As an additional or alternative, the sphere attachment has at least oneouter layer of unbreakable, in particular elastic, material and isarranged on the main body, and sufficiently largely dimensioned, in sucha way that damage to the auxiliary measuring instrument in the event ofimpact is minimized or prevented by the sphere attachment.

The disclosure also relates to a ground-based, for example geodetic,surveying system with a, in particular stationary, surveying devicehaving range-and-direction measuring functionality, in particular atotal station, and an auxiliary measuring instrument as described above,wherein the surveying device has a camera, by means of which atwo-dimensional image at least of a segment of the surface of the sphereattachment can be recorded, and the system has a decoding instruction (adecoding algorithm or decoding information), stored in a memory, fordecoding the code and also a controller with decoding functionality,which is designed to evaluate the camera image on the basis of thedecoding information in such a way that an orientation of the auxiliarymeasuring instrument can be bijectively determined.

In a development of the surveying system, the controller is designed insuch a way that, as part of the decoding functionality, a circle isfitted to the depiction of the sphere in the camera image, the center ofthe depiction of the sphere is ascertained by means of the fitted circleand the code that is present in a surface segment situated around thecenter is decoded.

Optionally, the surveying device of the surveying system has a base, atargeting unit, in particular a telescopic sight, which defines a targetdirection and can be pivoted with respect to the base about at least oneaxis, in particular two axes orthogonal to one another, for aiming atthe target, at least one angle meter and also an angle-measuringfunctionality for measuring the target direction, a range meter formeasuring a range from the target in the target direction, and acontroller with single-point determining functionality, in the executionof which, controlled by the controller, a position of a terrain pointdesignated with the aid of the auxiliary measuring instrument within anarea of terrain is determined on the basis of the measured targetdirection, the range between the target and the surveying device and theinclination and orientation of the auxiliary measuring instrumentdetermined on the basis of the sphere attachment.

Optionally, the targeting unit of such a surveying device has a beamsource for generating a measuring radiation, preferably laser radiation,and also has an optical unit for emitting the measuring radiation as afree beam in the target direction and an electro-optical detector fordetecting measuring radiation reflected by the target, from which therange from the target can be determined, wherein, in the execution ofthe single-point determining functionality, the target of the auxiliarymeasuring instrument is aimed at by means of setting the targetdirection, so that measuring radiation hits the target, and the rangebetween the target and the surveying device is determined by means ofthe measuring radiation.

As a further option, the surveying system has a drive for automaticallychanging the target direction and a target-tracking functionality, sothat, on activation of the target-tracking functionality, the targetdirection automatically follows a moving auxiliary measuring instrument,wherein the target-tracking functionality is based on an evaluation ofthe camera image of the sphere attachment, in particular wherein, aspart of the target-tracking functionality, images of the sphereattachment are continuously recorded and the target direction iscontinuously changed in such a way that the depiction of the sphere iskept at the center of the images.

Optionally, the code is designed in such a way that the code can bebijectively evaluated irrespective of the range of the surveying devicefrom the auxiliary measuring instrument (of course within certain limitsor up to a maximum distance). For example, the camera of the surveyingdevice is then equipped with an autofocus, in order to produce a sharpimage of the code automatically, irrespective of the distance.

The disclosure also relates to a method for determining the position ofa terrain point with the steps of aiming at the terrain point with anauxiliary measuring instrument as described above, measuring the rangefrom and direction in relation to the target provided by the auxiliarymeasuring instrument during the aiming at the terrain point from aground-based surveying device, in particular a total station, providingthe distance between the target and the terrain point (that is to sayknowing the previously fixed distance and/or measuring a variabledistance, for example by means of a laser distance meter of theauxiliary measuring instrument), determining the inclination andorientation of the auxiliary measuring instrument by means of imageevaluation of a camera image, in which at least part of the bodyprovided with a 2D code is depicted, and determining the position of theterrain point, starting from a known position of the surveying device,on the basis of the range and direction, the distance and theorientation.

Optionally, the method includes tracking of the auxiliary measuringinstrument on the basis of a series of images of the attached bodyrecorded by the surveying device, for example in that in each case adeviation of the position in the camera image of the sphere from anideal position (for example center of the image) is determined and, onthe basis of the deviations, the alignment of the surveying device iscontinuously changed, that is to say the target direction is made totrack the movement of the auxiliary measuring instrument.

The present disclosure also includes a computer program product or acomputer data signal, which is embodied by an electromagnetic wave, withprogram code, for controlling or carrying out the method according tothe disclosure for determining the position of a terrain point with anauxiliary measuring instrument described above with sphere coding, inparticular when the program is executed in a controlling and evaluatingunit of a surveying system according to the disclosure.

In a further aspect, the disclosure relates to a ground-based, inparticular geodetic, surveying system for surveying and/or staking outterrain points with a, in particular stationary, surveying device havingrange-and-direction measuring functionality, in particular a totalstation, and an auxiliary measuring instrument, wherein the surveyingdevice has a base, a targeting unit, in particular a telescopic sight,which defines a target direction and can be pivoted with respect to thebase about at least one axis, in particular two axes orthogonal to oneanother, a range meter and also a range-measuring functionality formeasuring a range from the target in the target direction, and at leastone angle meter and also an angle-measuring functionality for measuringthe target direction. The auxiliary measuring instrument has a handheldrod, the one end of which is intended for physically contacting aterrain point, and a target, which is attached to the rod, in particularat the other end, and can be aimed at by the surveying device, whereinthe target is attached to the rod at a distance from the contact endthat is defined and stored in a memory of the surveying system, so thata target position linked with the terrain point can be provided bycontacting the terrain point with the contact end.

Furthermore, the surveying system has a controller with evaluatingfunctionality, wherein, as part of the evaluating functionality, thetarget position can be determined on the basis of the target directionand the range between the target and the surveying device, and thecontroller has a calotte measuring functionality for determining theposition of a terrain point, wherein, in the execution of the calottemeasuring functionality, on the basis in each case of the targetdirection and the range, at least three non-coplanar target positionslinked with the terrain point are determined, wherein the non-coplanartarget positions are provided for example by at least three differentalignments or inclinations of the rod of the auxiliary measuringinstrument contacting the terrain point. Furthermore, as part of thecalotte measuring functionality, a calotte together with an associatedsphere center point is calculated on the basis of the three targetpositions and the stored distance between the target and the contactend, and the sphere center point is adopted as the position of theterrain point.

As an alternative, the target need not be attached at a defined, knowndistance from the contact end, in that the calotte calculation is notbased on three, but at least four, non-coplanar target positions. Apossibly known distance between the target and the terrain point canthen be optionally used for increasing the robustness of the calottecalculation or point determination or for verifying the result of thecalculation.

Optionally, the target of the auxiliary measuring instrument isretroreflective and the targeting unit has a beam source for generatinga measuring radiation and an optical unit for directionally emitting themeasuring radiation as a free beam in the target direction and also anelectro-optical detector for detecting measuring radiation reflected bythe target, so that the range from the target used for determining theposition of the target can be determined on the basis of detectedmeasuring radiation.

As a further option, the auxiliary measuring instrument has a userdisplay and the controller is designed in such a way that, as part ofthe calotte functionality, an instruction with respect to pivoting theauxiliary measuring instrument for generating the non-coplanar targetpositions, in particular with respect to an optimum, in particularhomogeneous and/or large-area, arrangement of the target positions, isdisplayed to a user on the user display.

In a development, the instruction is provided on the basis of a cameraimage of the auxiliary measuring instrument and its surrounding areawhen contacting the terrain point, wherein the camera image is recordedby means of a camera of the surveying device. Optionally, on the basisof the camera image, an ascertainment of a pivoting area to be excluded,which is unsuitable, in particular impossible, for an aiming of thecontacting auxiliary measuring instrument by means of the surveyingdevice, is performed, and/or an ascertainment of an optimum pivotingarea, which is particularly well-suited for an aiming of the contactingauxiliary measuring instrument by means of the surveying device, isperformed. As an alternative or in addition, the instruction or userprompting is based on at least the first determined target position.

As a further option, the instruction takes place graphically, in that agraphic indication of a pivoting area and/or individual pivotingpositions with respect to a pivoting movement to be executed of thecontacting auxiliary measuring instrument takes place on the userdisplay (for example recommended and/or unfavorable ranges orpositions). For example, the graphic indication is embedded in acamera-image-based depiction (that is to say a camera image or else avirtual depiction calculated therefrom) of the surrounding area of thecontacting auxiliary measuring instrument, wherein the camera image isrecorded by means of a camera of the surveying device and/or shows aperspective of the user of the auxiliary measuring instrument and/or itslocation.

Optionally, the target positions are kept in a temporary memory of thesurveying system and are abandoned or erased after completion of thedetermination of the terrain point.

The disclosure also relates to a method for determining the position ofa terrain point by means of a surveying system described above withcalotte measuring functionality, wherein the method comprises thefollowing steps: contacting the terrain point with the contact end ofthe auxiliary measuring instrument, pivoting the contacting auxiliarymeasuring instrument, so that at least three different target positionslinked with the terrain point are provided, determining the at leastthree target positions by means of the surveying device, calculating acalotte on the basis of the at least three target positions and theknown distance between the target and the contact end of the auxiliarymeasuring instrument by calculating the sphere center point associatedwith the calotte, whereby the position of the terrain point isdetermined by the sphere center point, or the steps of: contacting theterrain point with the contact end of the auxiliary measuringinstrument, pivoting the contacting auxiliary measuring instrument, sothat at least four different target positions, linked with the terrainpoint, are provided, determining the at least four target positions bymeans of the surveying device, calculating a calotte on the basis of theat least four target positions by calculating the sphere center pointassociated with the calotte, whereby the position of the terrain pointis determined by the sphere center point.

Optionally, during the pivoting, automatic target tracking and automaticdetermination of the target position are performed by the surveyingdevice.

As a further option, an output of a warning to a user takes place if thedetermination of the target positions is inadequate or impossible onaccount of absent or inadequate capability of aiming at the target bythe surveying device.

In a development of the method, an automatic or user-side assessment ofthe quality of the position of the terrain point takes place isperformed, wherein, with the quality assessed as insufficient, renewedor additional determination of target positions takes place. In thiscase, an automatic generation of a measure of quality, which is based onan overdetermination of the calculated calotte (for exampleoverdetermination due to the presence of more than the three or fournecessary positioning points or due to knowledge of the actual distancebetween the target and the contact point) optionally takes place isperformed for the assessment. As a further option, for a user-sideassessment, a graphic representation based on the position of theterrain point is generated.

As a further option, an automatic ending of the determination of targetpositions takes place is performed as soon as a predefined terminationcriterion is satisfied, in particular a maximum period of time haselapsed, a required accuracy has been achieved and/or a minimum numberof target positions has been determined.

Optionally, the determination of target positions and calculation of thecalotte proceed simultaneously in such a way that the calculation isperformed as soon as there are a minimum number of target positions andfurther target positions serve for the continuous updating and/orrefinement of the calculated calotte.

Some aspects also includes a computer program product or a computer datasignal, which is embodied by an electromagnetic wave, with program code,for controlling or carrying out the method for determining the positionof a terrain point by means of calotte calculation or calotte measuringfunctionality, in particular when the program is executed in acontrolling and evaluating unit of a surveying system.

In a third aspect, the disclosure relates to an auxiliary measuringinstrument which is designed to form together with a ground-based, inparticular stationary, surveying device having range-and-directionmeasuring functionality, in particular a total station, a system for, inparticular geodetically, surveying and/or staking out object points. Theauxiliary measuring instrument has a handheld main body of a definedlength, and at least one element which is arranged in a defined manneron the main body and is designed to measure the position and orientationof the auxiliary measuring instrument in interaction with the surveyingdevice. For this, a body, in particular a sphere, is attached at asecond end of the auxiliary measuring instrument. The body is in thiscase intended for the optical-image-based determination of the positionof the auxiliary measuring instrument by the surveying device.

Preferably, the body is the bearer of a 2D code on its surface and is inthis case designed in such a way that an orientation and range of thespherical attachment, and consequently the auxiliary measuringinstrument, can be determined (by the surveying device) by imageevaluation of a camera image of the 2D code and on the basis of storeddecoding information, for example in a memory of the surveying device.Together with a measured direction with respect to the auxiliarymeasuring instrument, the distance gives the position of the auxiliarymeasuring instrument in space or in relation to the surveying device, sothat altogether the location (orientation and position, six degrees offreedom) of the auxiliary measuring instrument can be determined on thebasis of the body.

Moreover, the auxiliary measuring instrument has a man-machineinterface.

Moreover, the auxiliary measuring instrument is designed in a pen-likeform and size, wherein an object point to be surveyed or marked out canbe aimed at in a one-handed manner with a first end of the auxiliarymeasuring instrument.

Preferably, the auxiliary measuring instrument can be ergonomically heldand guided with one hand, in particular for which the main body hasindentations and/or bulges adapted to the human hand, in particular agripping region for at least the thumb and index finger, and inparticular also the middle finger, of a user, and/or the massdistribution of the auxiliary measuring instrument is adapted in such away that its centroid satisfies ergonomic aspects.

Optionally, the auxiliary measuring instrument has an inertial measuringunit (IMU), so that the location of the auxiliary measuring instrumentcan be completely determined by a combination of measurement data of theinertial measuring unit and position data determined on the basis of thebody.

As a further option, the first end is designed as a probe ball withelectronic and/or mechanical correction of the measuring offset on thebasis of the size of the probe ball. In this case, the correctionpreferably takes place by the probe ball being attached in such a waythat, for measuring an object point, the probe ball is deflected exactlyabout the radius of the probe ball.

Optionally, the first end is designed as a self-triggering sensor tip,which on contact automatically triggers a measurement. Optionally, theend is exchangeable, in that the main body has a holder (connectingpiece), which is intended for receiving different tool and/or sensortips, in particular wherein the holder has a sensor system, which servesfor automatically identifying the respective tip. Optionally, in thecourse of the identification, an identification of the length of the tiptakes place, i.e. the measuring system is automatically notified of themeasuring or marking point of the tip.

As a further option, the tool and/or sensor tip is designed as a markingpen, in particular a felt pen, pencil or crayon, and/or an active tooltip, in particular a printer and/or a sprayer and/or a marking laser, inparticular a line laser, and/or is designed as a sensor tip, inparticular a (touch) probe and/or a metal detector, a line finder (forexample with a function for the active modulation of a signal onto theline) and/or a laser distance meter.

Optionally, the man-machine interface has a touch-sensitive displayand/or a scroll wheel and/or a microphone (for voice control) and/or alighting means for visual user information and/or a button. Such abutton is optionally designed as a triggering button that is separatelyformed and/or separately arranged on the main body, wherein thetriggering button is intended for triggering the position andorientation measurement of the auxiliary measuring instrument and/or theauxiliary measuring instrument has an active tool tip and/or sensor tipand the triggering button is intended for triggering an action of thetool tip (for example marking) and/or a measurement with the sensor tip.

As a further option, the auxiliary measuring instrument has a, inparticular removable, measuring tape of variable length, in particularwith an arresting function, wherein the measuring tape is intended forcircular constructions, in particular so that the center point of thecircle lies on the longitudinal axis.

In a development, the at least one element intended for the position andorientation measurement is designed as a sphere attachment, which bearson its surface a two-dimensional code, which can be bijectivelyevaluated by image processing of an image recorded with a camera of thesurveying device.

Optionally, the length of the auxiliary measuring instrument is variablein a defined manner, in particular in that the main body has at its oneend, defined by the longitudinal axis, a holder for receivingpole-shaped extension pieces, in particular wherein the holder has asensor system which serves for the automatic identification of therespective extension piece, and/or the main body is telescopicallydesigned, so that its length is variable, in particular steplessly,wherein the respectively applicable length can be measured by means of aposition encoder of the auxiliary measuring instrument or an integratedelectronic distance meter, which is for example arranged in an innercavity.

As a further option, the auxiliary measuring instrument has acommunications interface, in particular an IRDA or BLT interface, inorder thereby to communicate with the surveying device.

The disclosure also relates to a ground-based surveying system with a,in particular stationary, surveying device having range-and-directionmeasuring functionality, in particular a total station, and a pen-likeauxiliary measuring instrument as described above.

Optionally, the surveying device of the system has a base, a targetingunit, in particular a telescopic sight, which defines a target directionand can be pivoted with respect to the base about at least one axis, inparticular two axes orthogonal to one another, in particular wherein thetargeting unit has a beam source for generating a measuring radiationand also an optical unit for directionally emitting the measuringradiation as a free beam, at least one angle meter and also anangle-measuring functionality for measuring the target direction, and acontroller with single-point determining functionality, in the executionof which, controlled by the controller, a position of an object pointdesignated with the aid of the auxiliary measuring instrument within anarea of terrain is determined.

The disclosure also relates to a method for determining the positionand/or marking a terrain point with the steps of aiming at the objectpoint with a pen-like auxiliary measuring instrument as described above,determining the position and orientation of the auxiliary measuringinstrument during the aiming at the object point by means of aground-based surveying device, in particular a total station,determining the position and/or marking the object point (marking and/orsurveying), starting from a known position of the surveying device, onthe basis of the determined position and orientation of the auxiliarymeasuring instrument.

Optionally, in the course of the method, a continuous determination ofthe position and orientation of the auxiliary measuring instrument isperformed (tracking) and, on reaching a predefined position andorientation, the marking of the object point is automatically triggered,that is to say that, when the object point to be achieved is passedover, the point is automatically marked.

The present disclosure also includes a computer program product or acomputer data signal, which is embodied by an electromagnetic wave, withprogram code, for controlling or carrying out such a method fordetermining the position of a terrain point with the aid of such apen-like auxiliary measuring instrument, in particular when the programis executed in a controlling and evaluating unit of a surveying system.

A further aspect relates to a laser receiver for capturing a laser beamor laser light representing a position reference, for purposes ofconstructional activities or in the field of construction sites, with ahousing with a front surface and a rear surface, wherein the frontsurface has a line- or area-like laser detector for the detection of thelaser light and the rear surface is designed in such a way that thelaser receiver can be displaced along a large-area object surface and soas to follow the profile of the object surface. The object surface ispreferably a surface of a building, or similar at least partly planarsurfaces that are already known, for example already known on the basisof a plan of a building or other construction/design plan or model.

The laser receiver also has a marker, in particular a printer, whereinthe marker is designed and arranged in such a way that, in the state inwhich it is placed on the object surface, a physical marking can beapplied to the object surface in a marking zone. Furthermore, the laserreceiver has a controller, which is designed in such a way that, on thebasis of the position reference given by the captured laser light, amarking can be automatically applied by means of the marker to theobject surface positionally accurately at a planned or intendedposition, stored in an electronic memory, as soon as the plannedposition arrives in the marking zone, for example in that the laserreceiver at least approximately reaches or passes over the plannedlocation.

Optionally, the marker has a line-like or area-like marking regionand/or is designed as an inkjet printer and/or for printing texts and/orgraphics onto the object surface. Such graphics are for example 2D, 3Dbarcodes or QR codes, which serve for example for the injectiveidentification of measuring points. As a further option, the marker issuitable for printing on ceilings (printing direction “upward”, againstthe force of gravity) and/or additionally designed for applying asealing of the marking, for example by means of a clear varnish or aprotective film.

As a further option, the planned position is stored as part of aconstruction plan, such as for example a plan of a building.

As a further option, the laser receiver is designed for manualdisplacement, in particular in that it has a shaping of the housing thatcan be held by a hand and/or a continuation attached to the housing thatcan be held by a hand.

In a development, the laser receiver has at least one position encoderfor the continuous determination of the position and/or orientation ofthe laser receiver, in particular wherein the controller is designed insuch a way that regions in which no position referencing by means of thelaser light is possible can be bridged by means of position data of theposition encoder and/or the position encoder is designed as a targetthat can be measured by a surveying device, in particular aretroreflector, and/or at least three lighting means which are arrangedin a defined manner on the housing and can be captured in an image by acamera, and/or an inertial measuring unit, for example with accelerationsensors and rate-of-rotation sensors, and/or optical or mechanicallinear encoders.

Optionally, the rear surface has wheels and/or caterpillars fordisplacing the laser receiver. As a further option, the laser receiverhas a cleaning device for cleaning the object surface, in particular hasa device for spraying compressed air and/or solvent and/or a drive forindependent displacement.

The disclosure also relates to a mobile construction site printer forautomatically printing construction site markings onto planar surfaces,in particular surfaces of a building, in the course of construction workor similar construction-related work over a large area, for example whenerecting or converting buildings or parts of a building, for examplealso assembly and disassembly work in trade fair halls, or on otherobjects of a large area, such as ships or aircraft. The printer has aprinting zone; the printer is designed in such a way that it can bemoved by a user by hand along the object surface and so as to follow theprofile of the object surface, wherein the movement along the objectsurface has the effect that the translation with respect to onedirection and the rotation with respect to two axes are predefined. Theprinter has at least one position encoder, for example a yaw-anglesensor in combination with an inclination sensor, whereby the positionwith respect to the two remaining translational degrees of freedom andthe one remaining rotational degree of freedom of the printer can becontinuously determined. Furthermore, the printer has a controller,which is designed in such a way that the (continuously determined)position of the printer can be continuously compared with a plannedposition on the object surface, stored in an electronic memory, so thata construction-site marking can be automatically printed positionallyaccurately at the stored planned position onto the object surfaceuninterruptedly during the movement as soon as the planned positionarrives in the printing zone, that is to say for example the printer atleast approximately passes over the planned position in the course ofthe movement.

The disclosure also relates to a mobile construction-site printer forautomatically printing construction-site markings on object surfaces inthe course of construction work, wherein the printer has a printingzone, the printed can be moved in a mobile manner along an objectsurface, the printer has at least one position encoder, so that thelocation and alignment of the printer in relation to the object surfacecan be completely determined, and the printer has a controller, which isdesigned in such a way that the location and alignment of the printercan be continuously compared with respect to a planned position on theobject surface, stored in an electronic memory, so that aconstruction-site marking can be automatically printed positionallyaccurately at the stored planned position onto the object surfaceuninterruptedly during the movement as soon as the planned positionarrives in the printing zone.

The developments described above of the laser receiver also be appliedcorrespondingly to a respective mobile construction-site printer.

The disclosure also relates to a method for physically marking a plannedposition, stored in an electronic memory, in particular as part of aplan of a building, on an object surface for purposes of constructionalactivities, with the steps of providing a position reference by means offree-beam laser light, displacing a laser receiver having a marker, inparticular a printer, on the object surface, capturing the laser lightrepresenting a position reference by means of the laser receiver,electronically controlled automatic positionally accurate physicalmarking of the planned position, retrieved from the memory, on theobject surface during the displacement on the basis of the positionreference given by the captured laser light as soon as the laserreceiver is at least approximately brought over the planned position.

The disclosure also relates to a method for marking a planned position,stored in an electronic memory, in particular as part of a plan of abuilding, on an object surface for purposes of constructionalactivities, with the steps of moving a mobile construction-site printeralong the object surface, wherein the position, and optionally also theorientation or alignment, of the printer is continuously determined,automatically continuously comparing the respective position with theplanned position, stored in the electronic memory, on the objectsurface, automatically positionally accurately printing a marking at theplanned position on the object surface during the movement as soon asthe laser receiver has at least approximately passed over the plannedposition, in particular wherein an interruption of the movement is notrequired for the printing.

Optionally, in the course of these methods, in addition to the positionmarking, meta data stored in an electronic memory are retrieved and arepresentation reproducing the meta data, in particular a text and/or agraphic, is applied to the object surface by means of the marker orprinter during the position marking.

Optionally, before the marking, a cleaning of the object surface isperformed at the planned position by means of the laser receiver or themobile printer. As a further option, after the marking, the applicationof a protective layer to the marking is performed, for example theapplication of a protective coat or film.

The present disclosure also includes a computer program product or acomputer data signal, which is embodied by an electromagnetic wave, withprogram code, for controlling or carrying out such a marking or printingprocess for applying a marking to an object surface.

A further aspect relates to a method for surveying and/or marking pointson an object on the basis of planned positions for purposes ofconstructional activities, with the steps of setting up a stationarysurveying device at a first known positioning in a surrounding area ofthe object, wherein the surveying device has a base, a targeting unit,in particular a telescopic sight, which defines a target direction andcan be pivoted with respect to the base about at least one axis, inparticular two axes orthogonal to one another, a beam source, inparticular a laser source, for generating radiation and also an opticalunit for emitting the radiation as a free beam in the target direction,wherein the free beam serves for surveying and/or marking object points,and in particular a range meter and also a range-measuring functionalityfor measuring a range from the target in the target direction, at leastone angle meter and also an angle-measuring functionality for measuringthe target direction, and a controller with single-point determiningfunctionality, and also a memory, in which input or surveyed positionscan be stored, in particular as part of a plan of a building or room.

Also performed in the course of the method are the steps of retrievingfrom the memory a set of object points of the object to be surveyedand/or to be marked, surveying and/or marking from the first positioningobject points of the set of object points that can be surveyed and/orcan be marked from the first positioning by means of the free beam, onthe basis of the target direction, ascertaining missing object points ofthe set of object points, relocating the surveying device to a second,unknown positioning in the surrounding area of the object, automaticallydetermining the second positioning by the surveying device on the basisof the knowledge of the first positioning, so that the secondpositioning is known, and surveying and/or marking missing object pointsby means of the free beam from the second positioning.

As an option, before the relocation, a positioning proposal suitable forthe second positioning is at least approximately ascertained by thecontroller of the surveying device, on the basis of stored positions,and the positioning proposal is displayed to a user on a display.

Optionally serving as a criterion by which the positioning proposal iscalculated is a calculated (theoretical) angle of incidence of the freebeam on the object surface that contains an object point still to besurveyed. For such surveying or marking operations, perpendicularincidence is optimum. For this reason, a positioning that allowsperpendicular incidence, or at least incidence that is as perpendicularas possible, is sought, either for a respective or the most importantobject point to be achieved or for a set of object points, then forexample in the form of an optimum for the mean value of all the anglesof incidence of all the object points of the set.

As a further option, information concerning a target direction inrelation to at least one of the positions that cannot be marked is takeninto account in the ascertainment of the positioning proposal.

Optionally, the display of the positioning proposal takes place isperformed in a graphic form, in particular embedded in a visualizationof a plan of a building or room or embedded in a 2D or 3D panoramicimage, recorded in situ, of the surrounding area and/or as an augmentedreality representation in a live video image of the surrounding area,for example displayed on AR glasses.

In a development of the method, the automatic determination of thesecond positioning is performed on the basis of a depiction of thesurrounding area produced by the surveying device in the secondpositioning, in particular wherein the depiction of the surrounding areais produced by means of a camera image of the surveying device and/or alaser scan carried out by means of the free beam. Optionally, in thecourse of the automatic determination of the second positioning, thedepiction of the surrounding area of the second positioning is comparedwith a depiction of the surrounding area produced in the firstpositioning, in particular wherein positions that can be seen in bothdepictions of the surrounding area and are marked from the firstpositioning serve as a position reference and/or are compared with astored digital plan of a building or room.

As an alternative or in addition, the automatic determination of thesecond positioning is performed by means of a structure-from-motionalgorithm on the basis of measurement data of an inertial measurementunit of the surveying device and/or a series of camera images recordedwith the surveying device.

The present disclosure also includes a computer program product or acomputer data signal, which is embodied by an electromagnetic wave, withprogram code, for controlling or carrying out such a method forsurveying and/or marking points on an object on the basis of plannedpositions for purposes of constructional activities.

Some aspects also relate to a stationary surveying device for surveyingand/or optically marking points on an object on the basis of plannedpositions for purposes of constructional activities, wherein thesurveying device has a base, a targeting unit, in particular atelescopic sight, which defines a target direction and can be pivotedwith respect to the base about at least one axis, in particular two axesorthogonal to one another, a beam source, in particular a laser source,for generating radiation and also an optical unit for emitting theradiation as a free beam in the target direction, in particular a rangemeter and also a range-measuring functionality for measuring a rangefrom the target in the target direction, and at least one angle meterand also an angle-measuring functionality for measuring the targetdirection. Furthermore, the device has a controller with single-pointdetermining functionality and a memory, in which input or surveyedpositions can be stored, in particular as part of a plan of a buildingor room, wherein the controller is designed for performing the methoddescribed above for surveying and/or marking points on an object on thebasis of planned positions for purposes of constructional activities.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in greater detail below on the basisof the embodiments and application procedures schematically representedin the drawings.

In the specific figures:

FIG. 1 shows an example of a surveying system with an auxiliarymeasuring instrument with spherical coding,

FIG. 2a-d show an example of an image evaluating operation with respectto decoding,

FIG. 3 shows an example of an embodiment of a coding,

FIG. 4a,b show an example of a surveying system with calotte measuringfunctionality,

FIG. 5a,b show examples of methods for position determination by meansof producing a calotte,

FIG. 6 shows an example of surveying with the aid of a calotte measuringfunctionality,

FIG. 7a-c show a development of the surveying system with calottemeasuring functionality,

FIG. 8a,b show a first example of an embodiment and application of apen-like auxiliary measuring instrument,

FIG. 8c shows in cross section a further exemplary embodiment of ameasuring pen,

FIG. 8d shows an embodiment of a pen with a probe ball,

FIG. 9a-e show further embodiments of a pen-like auxiliary measuringinstrument,

FIG. 10 shows a first example of a laser receiver with markingfunctionality,

FIG. 11 shows an example of a laser receiver or construction-siteprinter with a position encoder,

FIG. 12 shows a further example of a laser receiver or construction-siteprinter with a position encoder, and

FIG. 13a-c show an example of a method for surveying and/or markingobject points with relocation of the surveying device.

DETAILED DESCRIPTION

FIG. 1 shows purely schematically an example of a surveying system withan auxiliary measuring instrument with spherical coding. The system hasan auxiliary measuring instrument 20, which can be carried by a user andis designed as a plumbing pole. The instrument 20 has an elongate body23 with a longitudinal axis 25 a. The plumbing pole 20 or thelongitudinal axis can be handily aligned by a user 29 with a terrainpoint 28 to be surveyed or to be marked out, so that the auxiliarymeasuring instrument 20 can be used to aim at the terrain point 28. Sucha terrain point 28 is in this case located for example outdoors orwithin a building. The distance D from a reference point 21 of theplumbing pole 20 to the terrain point 28 is in this case already knownand stored in a memory of the surveying system. As an alternative to therepresentation shown, there are also known auxiliary measuringinstruments 20 that aim at the terrain point 28 contactlessly, forexample by means of a laser distance meter, and measure the thenvariable distance from the reference point 21 to the terrain point 28and pass it on to a memory or an evaluation.

The surveying system also has a surveying device 30, for example a totalstation. The surveying device 30 has a base 33 and an attachment 32,which is arranged on the base 33 pivotably in relation to the latterwith reference to a vertical axis z. The mount 33 has a targeting unit34, which is rotatable with respect to a horizontal axis y.Consequently, the alignment of the targeting unit 34 or the targetdirection can be varied by rotation about the two axes z and y, whereinthe respectively applicable alignment is measured by angle encoders.

The targeting unit 34 includes a light source, for example a laser,which generates measuring radiation which is emitted with the aid of acorresponding optical unit as a measuring beam M, for example as a laserbeam, directed onto the auxiliary measuring instrument 20, or to be moreprecise onto a target 25 of the auxiliary measuring instrument. Thetarget 25 is in this case in a known spatial relationship with thereference point 21, in the example because the center of the target 35coincides with the reference point 21. On the basis of the measuringradiation, the range E from the total station to the auxiliary measuringinstrument 20 or to the reference point 21 is determined, for examplewith the aid of a transit time of measuring beam pulses and/or by theinterferometric principle. Usually, the emitted light is in this caseretroreflected by the target 25, so that it can be received by thesurveying device 30 and can be detected by means of a detector.

From knowledge of the direction of emission, the range E and thedistance D, the position of the terrain point 28 in relation to thesurveying device 30 (or to be more precise in relation to a referencepoint of the surveying device 30) can consequently be determined. If theposition of the surveying device 30 with reference to an externalcoordinate system is known, the position of the terrain point 28 in thiscoordinate system can consequently also be determined. In the case of ageodetic survey, the coordinate system is for example the UTM coordinatesystem.

Apart from the variables mentioned, knowledge of the alignment andinclination of the auxiliary measuring instrument 20 (in relation to thesurveying device 30 or with reference to the coordinate system) is alsonecessary however for the injective determination of the position of theterrain point. This can be achieved by the plumbing pole 20 always beingpositioned perpendicularly on the terrain point 28, so that theorientation is already known. This predetermined attitude of theauxiliary measuring instrument 20 is not always possible, however, forexample when corners of a building are used as the terrain point 28, orat least can scarcely be maintained exactly by the user 29,especially—but not only—when a contactlessly operating auxiliarymeasuring instrument 20 is concerned.

For this reason, the auxiliary measuring instrument 20 has an attachment22, with the aid of which the orientation of the auxiliary measuringinstrument 20, i.e. inclination, roll and yaw or azimuth angle, can bedetermined. The attachment 22 has the form of a sphere, which isarranged on the body 23 in a known spatial reference relationship withthe longitudinal axis 25 a, in the example in that the center 26 of thesphere lies on the longitudinal axis 25 a, whereby the longitudinal axis25 a can be regarded as a North-South axis of the sphere, andconsequently an equator 27 of the sphere is predefined.

An optical, two-dimensional code 24 is arranged in a distributed manneron the surface of the sphere. An image of the sphere 22 or the code onits surface is recorded by means of a camera 31, arranged in a definedmanner, of the surveying device 30 (as an alternative to therepresentation shown in FIG. 1, the camera 31 may for example also bedesigned as an on-axis camera, that is to say without any offset inrelation to the optical axis of the targeting unit 34). The code 24 isdesigned in such a way that, by means of image evaluation of the cameraimage, the orientation of the sphere 22, and consequently of thesurveying pole 20 in relation to the camera 31 and consequently inrelation to the surveying device 30, can be bijectively ascertained.That is to say that the inclination of the longitudinal axis 25 a andits alignment (rotating position of the auxiliary measuring instrument20 about the longitudinal axis 25 a) are bijectively determined on thebasis of a code (segment) visible from the surveying device 30 by meansof image evaluation/processing.

The code 24 runs around the surface, at least in a plane runningperpendicularly to the longitudinal axis 25 a and through the spherecenter point 26, so that code 24 can be seen, and consequently theorientation can be bijectively determined, from any side view. In theexample, the code 24 is even formed in a distributed manner over theentire surface of the sphere and in such a way that, in any location(apart for example from instances where it is covered by the main body)of the auxiliary measuring instrument 20, this location can bedetermined. As an alternative, for example, an upper region and a lowerregion of the sphere are code-free or the sphere 22 is cut off at thetop and bottom (i.e. the two “polar caps” of the sphere 22 are notprinted with code or are not present at all), on the assumption thatextreme inclinations of the auxiliary measuring instrument 20 or thelongitudinal axis 25 a, for example by more than 60° with respect to thevertical z, on the assumption that do not occur in the applicationintended for the auxiliary measuring instrument 20 or surveying systemconcerned, and therefore do not have to be determinable.

As an option (that is not represented), the pole 20 additionally has alight for illuminating the attachment 22, so that the attachment 22, orto be more precise the code 24, can be seen sufficiently well in thecamera image even in poor outside light conditions. For this, the sphere22 is designed for example as a translucent hollow body, in the interiorof which there is a light source, so that the surface of the sphere isilluminated from the inside.

As a further option, the sphere attachment 22 additionally serves as aprotective body for absorbing impact on the auxiliary measuringinstrument 20. For this purpose, the sphere 22 is positioned, forexample as shown in FIG. 1, at the upper end of the pole 20 and is ofsuch a large diameter that, if the plumbing pole 20 falls over from theupright position, the pole 20 hits the ground with the sphere 22, whichis for example produced from an elastic or otherwise unbreakablematerial or at least has a protective layer of such material. Theremaining parts of the auxiliary measuring instrument 20 areconsequently protected by the sphere 22 from such mechanical damage.

As an additional option, the target 25 is integrated in the attachment22. For example, retroreflective elements (for example in the form of aretroreflective film or layer or individual retroreflectors that aredistributed segmentally in a way similar to in the case of a soccerball), which perform the function of the retroreflector 25, aredistributed over the surface of the sphere. As a further alternative,direction and range determination are performed for example in animage-based manner, in that the sphere attachment 22 or the code 24serves not only for orientation determination, but also for positiondetermination, and consequently as a target 25. For this purpose, therange is ascertained, for example on the basis of the size of the sphere22 and/or of the code in the image in comparison with the known actualsize, and the direction is ascertained on the basis of the position ofthe sphere 22 and/or of the code in the image. The code is either thesame code that also codes the orientation, that is to say thereforeperforms a dual function, or an additional code serving purely forposition coding.

FIGS. 2a-2d show an example of an image evaluating operation of a cameraimage 35, which has been recorded by the camera of the surveying device.Depicted in the image 35 is part of the auxiliary measuring instrument,including the sphere attachment 22 (see FIG. 2a ).

Thus, in the image a circle geometry 36 is adapted (“fitted”) as well aspossible to the depicted circular form of the sphere 22 by means of analgorithm known per se, as indicated in FIG. 2 b.

In FIG. 2c it is shown how the center Z of the depicted attached sphere22 is determined on the basis of the known center point of the circlegeometry 36.

A region or segment 37 of the image 35 or of the depicted surface of thesphere 22 that is situated at the center Z or represents a centralsegment of the imaging depicting the surface of the sphere (see FIG. 2d) is then used for the actual code evaluation or decoding.

In other words, in the image the silhouette of the sphere in the imageis determined and at its centroid a region of interest (RoI) isascertained and used for the decoding, and consequently orientationdetermination. Concentration on or restriction to a segment 37 of thecode arranged at the center Z of the depicted image has the advantagethat the influence of distortions of the three-dimensional surface ofthe sphere in the two-dimensional camera image 35 is consequently keptas small as possible, in particular to the extent that it is negligibleand does not have to be taken into account in the decoding. That is tosay that the segment 37 is chosen such that on the one hand sufficientcode for the bijective determination of the location of the sphere inrelation to the camera or the total station is visible/available in thesegment 37, on the other hand the image evaluation does not have todiffer from an evaluation of a code that is arranged on a plane which islocated perpendicularly to the recording direction or parallel to theimage plane.

As an option, a determination of the location of the center Z in theimage or the deviation of the location from a desired position isperformed, for example from the center of the image. On the basis ofthis offset, the target direction of the surveying device is thentracked, so that the center Z comes to the desired position. This allowsan exact alignment of the target direction or, in the case of a movingauxiliary measuring instrument, tracking of the target.

FIG. 3 shows purely schematically an example of a code on the basis ofwhich the orientation of the sphere attachment, and consequently theauxiliary measuring instrument, can be bijectively determined in asegment 37 (cf. FIG. 2d ). In the example, the code is of two parts, insuch a way that it has first code elements 38 a-38 c, which serve forthe bijective coding of a first direction, for example the length (withrespect to the equator 27 from FIG. 1). Furthermore, there are secondcode elements 39 a-39 c, which bijectively code the width as a seconddirection. By decoding the two code parts 38, 39, it is consequentlyspecified bijectively which “location” on the sphere can be seen in thesegment 37, and consequently the orientation of the sphere in relationto the image (segment).

In the example, the code is in this case of such a form that inprinciple already a respective element 38 a, 38 b or 38 c or 39 a, 39 b,39 c alone bijectively codes the length or width. The presence of ineach case three code elements 38 a-c, 39 a-c that is shown serves forproviding various resolution stages, so that similar resolutions can beascertained from different ranges between the camera and the sphere, andconsequently there is the same accuracy of the orientation determinationover all measuring ranges. For example, a respective element 38 a and 39a with a comparatively coarse structure serves for great ranges, arespective element 38 b and 39 b with medium resolution serves formedium ranges and a respective element 38 c and 39 c with a finestructure serves for small ranges or measurements in the near range.Consequently, such a code is also suitable for use with surveyingdevices with zoom-free cameras.

As an alternative or in addition, such a code division with finer andcoarser code elements serves for increasing the robustness of themeasurement by providing redundancy and/or providing coarse (medium) andfine resolution. For example, in a first step a coarse, bijective lengthis determined on the basis of the code strip 38 a and in a second stepis refined by the code strip 38 b and/or 38 c, for which the code strips38 b and/or 38 c do not have to code bijectively.

The code elements 38, 39 for the coding of two different directions maydiffer by different geometries, as indicated in the example. As analternative or in addition, they differ by different colors, for examplein that the length coding 38 is in green and the width coding 39 is inred. Such different colors (as a difference from the representationshown) also facilitate for example a superposed arrangement of codeelements, so that the limited space of the surface of the sphere can becovered more densely.

FIG. 4a schematically shows an example of a surveying system 60, whichhas a calotte measuring functionality. The surveying system 60 has asurveying device 61, designed for example a total station, and anauxiliary measuring instrument 66, which can be optically aimed at bythe surveying device 60 and is designed for example as a plumbing polewith a retroreflector. The surveying device 61 has a base 64 and also anupper part 65, which is arranged on the base 64 and is rotatable inrelation to the base 64 about an axis z. The upper part 65 in turn has adefined tilting axis y, about which an targeting unit 63 can be pivoted.The targeting unit 63 is for example designed as a telescopic sight. Thetargeting device 63 defines a target direction x, which can be varied bypivoting about the two axes z, y. For determining the respectivelyapplicable target direction y, the surveying device has at least oneangle meter, for example to establish the rotational position about theaxes y and z.

The auxiliary measuring instrument 66 of the surveying system 60 has atarget 68, which can be aimed at by the surveying device 61 by means ofthe targeting device 63, and moreover a range E (in target direction x)can be measured by means of a range meter of the surveying device 61. Inthe example, for this purpose a measuring beam 62 is emitted by thesurveying device 61 in target direction x, retroreflected by the target68, the beamed-back measuring beam 62 is detected by the surveyingdevice 61 and the range E is determined, for example by means of theFizeau principle, transit-time measurement or interferometrically. Knownfrom the prior art are for example alternative image-basedtarget-position determining methods, in which the target 68 has specificfeatures, with the aid of which the range and orientation of the target68 can be measured on the basis of an image of the target 68 that isrecorded by a camera of the surveying device 61 (i.e. the cameratogether with a corresponding image-evaluating algorithm forms the rangemeter). Further alternatives are for example stereometry or rangeimages. Knowledge of the range E and the target direction x canconsequently be used in any event for determining the position of thetarget 68 in relation to the surveying device 61 and, with a knownabsolute position of the surveying device 61, also the absolute positionof the target 68.

The target position in turn serves for determining the position of aterrain point 67, which is to be surveyed for example in the course ofgeodetic surveys or in the course of construction activities. To be ableto obtain an injective inference of the position of the terrain point 67from the target position, the target 68 must be in an injective relativeposition in relation to the terrain point 67.

This is achieved in surveying systems 60 or surveying methods known fromthe prior art by the target 68 attached to the auxiliary measuringinstrument 66 being at the defined, known distance from the end of theauxiliary measuring instrument 66 that contacts the terrain point 67,and consequently also at a known distance from the terrain point 67.Furthermore, the auxiliary measuring instrument 66 is set upperpendicularly on the terrain point 67, so that the target 68 isperpendicularly above the terrain point 67. As a result, the targetposition and the terrain point position are injectively linked. Adisadvantage of this method is that a perpendicular alignment cannot beeasily maintained and is even not always possible, for example becausethe terrain point 67 is an inner or outer corner of a building.

According to the disclosure, this disadvantage is overcome by thesurveying system 60 having a calotte measuring functionality, asexplained in greater detail below on the basis of the lower part of FIG.4a . The auxiliary measuring instrument 66 is positioned with itscontact end 69 on the terrain point 67. Without breaking the contact,i.e. the contact end 69 remains fixed on the terrain point 67, theauxiliary measuring instrument 66, and consequently the target 68attached to its other end, is thus pivoted. The target 68 therebyassumes different target positions 70, which on account of the rigidconnection to the terrain point 67, are all linked with the terrainpoint 67.

As illustrated in FIG. 4a and also in FIG. 4b , the pivoting movement 72with the fixed distance R between the target 68 and the point 67, allowsthe target 68 to assume different target positions 70, which are notcoplanar to one another and are all located on a surface of a sphere orsegment of a surface of a sphere or calotte 71, the center point ofwhich is the sought terrain point 67. Consequently, the sought positionof the terrain point 67 can be determined from knowledge of the calotte71.

For this purpose, either at least four or at least three of thedifferent target positions 70 are determined by means of the surveyingdevice 61 and used as a basis for calculating the calotte 71, forexample by means of a best-fit algorithm for minimizing the squares ofthe distances of the target positions 70 in relation to the surface ofthe sphere. Generating the target positions 70 either takes placemanually or automatically in the sense that an optionally presentautomatic target tracking, known in principle, of the surveying device61 is used as part of the calotte measuring functionality, in order tochange the target direction x automatically so as to follow the pivotingof the target 68 and thereby to continuously determine target positionsor calotte points 70. The continuous determination of target positionsis in this case performed for example at a previously predefinedmeasuring rate, for example every tenth of a second, half a second orevery second, or—possibly dynamically—adapted to a speed of the pivotingmovement, measured for example on the basis of at least two measuredtarget positions and their difference in time.

Three target positions 70 are in principle already sufficient forcalculating the calotte 71 if the distance R from the target 68 to theterrain point 67, that is to say the sphere radius R, is known, that isto say this distance or the height of the plumbing pole 66 is stored forexample in a memory of an evaluating unit of the surveying system. Onthe basis of four instead of only three target positions 70, the calotteor the sphere center point 67 can be injectively calculated even withoutknowledge of the distance or sphere radius R. A stored distance R is insuch a case optionally used for increasing the robustness of theposition determination or for verification, for example in that a sphereradius R ascertained on the basis of the at least four target positions70 is compared with the stored distance in order to determine the extentof any deviations.

As a further option, such an extent of the deviation is in this caseused as a measure for assessing the quality of the calotte or positioncalculation. The smaller the deviation, the better the quality. As analternative or in addition, another type of overdetermination of thecalotte is used to provide a measure of quality. If there are more thanthe three or four minimum target positions 70 with which the calotte 71or the center point 67 has been calculated, the accuracy or quality ofthe calculated calotte 71 is ascertained on the basis of the “excess”target positions.

The assessment of the quality for example on the basis of a measure ofquality is in this case performed automatically and/or by a user, asfurther explained on the basis of the following figures.

FIG. 5a shows a first example of a method for position determination bymeans of producing a calotte. In step 73, the contact end of theauxiliary measuring instrument is brought into physical contact with theterrain point. Subsequently, in step 74, the calotte measuringfunctionality is started. The auxiliary measuring instrument is pivotedabout the terrain point and the target is thereby brought into varioustarget positions, which are all at the same distance from the terrainpoint, and these target positions (calotte points) are determined withthe aid of the surveying device (step 75).

As soon as at least four (or, when using the defined target height orpole length, at least three) calotte points have been produced, theradius and center point are calculated by the best-fit method (step 76)and further calotte points are generated by further movement of thetarget and further target position determination (step 77). On the basisof these further target positions, the radius and sphere center pointare updated or refined and in the example are displayed on a display ofthe surveying system, for example in the form of a graphic (step 78).Consequently, in this variant the determination of target positions andcalculation of the calotte take place simultaneously: as soon as theminimum number of for example four target positions are obtained, acalotte is calculated and this is continuously newly calculated orrefined on the basis of the continuously supplied target positions.Optionally, the provisional calotte or the provisional sphere data is orare displayed, for example graphically, by a user display of the system,so that already during the calotte measuring operation the user obtainsinformation concerning the measurement result and if applicable canassess this information and for example influence, adapt or terminatethe measuring operation.

The surveying system then assesses in step 79 a the accuracy or qualityof the calculated calotte, for example on the basis of a measure ofquality as mentioned above. If the accuracy is below a predeterminedlimit, that is to say there is sufficient quality, in step 80 thecoordinates of the sphere center point or terrain point are permanentlystored and the calotte measurement is ended (step 81). Otherwise, thegeneration of target positions is continued. The calotte points ortarget positions that served for the calculation of the calottes, andconsequently the terrain point position, are for example only kept in atemporary store for the method, and are not permanently stored buterased after final determination of the terrain point.

FIG. 5b represents a variation of the method according to FIG. 5a . As adifference from the foregoing, a check of the calotte or of the spherecenter point, and if applicable the sphere radius, is performed by theuser in a step 79 b and it is decided by the user whether the terrainpoint position is exact or sharp enough or whether a further or renewedtarget position determination is performed in order to improve or newlycalculate the sphere center point.

As a further difference from FIG. 5a , a calculation of the calotte orthe sphere center point is only performed in a step 78 b after thedetermination of target positions in a step 76 b has been completed. Asa criterion that serves for deciding on the ending of the targetposition determination, for example a time period and/or number ofmeasured values is used. For example, it is stipulated that a setminimum measuring quality is to be achieved or a minimum number of tentarget positions are to be determined or the measurement is ended aftertwo minutes. Then, the calotte is calculated on the basis of these tenpositions or the positions ascertained within the two minutes.

FIG. 6 shows an example of how a terrain point 67 that cannot besurveyed with conventional surveying systems, or only very laboriously,can be advantageously surveyed by means of the calotte measuringfunctionality. In the example, the terrain point 67 is a location of abuilding 82 at the interface of the roof and wall. It is not possiblethere for the surveying pole 66 to be set up perpendicularly, butcontacting with its contact end and rotating movement with the point onthe building as a fixed point as shown. Consequently, the three or fourtarget positions necessary for the calculation of a calotte 71 can begenerated, on the basis of which the sphere center point is calculated,whereby the sought position of the terrain point 67 is determined.

FIGS. 7a-c illustrate a development of the surveying system 60. In theexample, a controller of the system 60 is designed in such a way that aninstruction, for example a graphic instruction as shown, for thepivoting of the auxiliary measuring pole 66 to be performed by the user88 is displayed to the user on a display 86 of the auxiliary measuringinstrument 66 (see FIG. 7a ). That is to say that the system 60 promptsthe user 88 with respect to providing the positions of the target 68.The prompting or instructing takes place in this case for example by anoptimum arrangement or distribution of the target positions for thecalculation of the calotte being achieved. For example, the user 88 isinstructed to pivot the auxiliary measuring instrument 66 in such a waythat a distribution of the target positions that is as homogeneous oruniform as possible, or is over as large an area as possible, isachieved.

In the example, for providing graphic user prompting by means of a totalstation camera 83, which has a field of view 83 a, which is at leastcoarsely aligned in the targeting direction x, an image 85 of theauxiliary measuring instrument 66 set up on the terrain point 67together with the user 88 and a segment of the (measuring) surroundingarea is recorded. On the basis of this image 85 recorded by thesurveying device 61, individual target positions to be attained or atarget position area are automatically or manually predefined. These aregraphically marked in the image or a pivoting movement that leads to thetarget positions to be provided (arrow 87) is graphically marked in theimage 85. The instruction image 85 thus prepared is then transmittedwirelessly (indicated by the symbols 84) to the display 86 of themarking pole 66 and displayed there to the user 88 on the display 86.

Since the camera image 85 is advantageously recorded from the viewpointof the surveying device 61, the target positions suitable for an optimumcalculation of a calotte can be estimated particularly well in it. Thus,instead of a generalized instruction, an instruction deliberatelyadapted to the specifically applicable measuring situation andspatial/locational circumstances can be produced and made available tothe user 88.

Such an ascertainment of a suitable target position area 89 isschematically shown in FIG. 7b . The surveying device 61 records fromits location, with its camera 83, an image of the measuring locationaround the terrain point 67, which includes at least the correspondingpart of the building 82 and the user 88 together with the appliedauxiliary measuring instrument 66. On the basis of this camerarecording, the controller of the surveying system ascertains an area 89within which the user 88 is to pivot the target 68. Areas that cannot beseen or aimed at by the surveying device 61, for example on account ofbeing covered by the building 82, are thus deliberately excluded. Anadvantage of the surveying device perspective as a basis for theinstruction of the user 88 is that from there it can be estimated withcertainty which spatial areas or positions of the auxiliary measuringinstrument are suitable for the calotte measurement and which are not.

FIG. 7c shows an example of the graphic instructional representation ona user display 86. In an image 85, the perspective of the user of themeasuring surrounding area with the terrain point 67, the corner of thebuilding 82 and the measuring pole 66 is artificially replicated on thebasis of an image of the surveying camera. In this image 85, an area 87a within which the user is intended to pivot the auxiliary measuringinstrument 66 is also indicated. As an option that is not shown, it isin this case indicated in a continually updated manner which parts ofthe area 87 a the user has already covered, so that the user is keptinformed the whole time which segment of the area 87 a has not yet beencovered. As a further option, as shown, apart from the image 85imitating the viewpoint of the user, a further image 85 a is displayed(as an image in the image), reproducing for example the viewpoint of thesurveying device or its camera. Also this image optionally hasuser-prompting information, for example as shown the indication of anarea 87 b that is unsuitable for target position determination, forexample because of a visual obstacle, and into which the user thereforeshould not move the target.

As an alternative or in addition to a camera-image-based instruction,the instruction is based on the first already measured target positionor positions. That is to say that at least one target position isdetermined and on this basis it is for example calculated by the systemcontroller which further target positions are to be assumed. As afurther option, the display 86 is used to output a warning to the user88 if target positions provided by the user cannot be determined, oronly insufficiently, or are not suited or only poorly suited for thecalotte calculation. Such an optical or else acoustic warning allows theuser 88 to correct the pivoting.

FIG. 8a shows a first exemplary embodiment of a pen-like auxiliarymeasuring instrument 40. The auxiliary measuring instrument 40 resemblesin size and shape a pen; it has an elongate main body 42, the one end ofwhich is designed as a tip 43. This tip 43 is intended for designating apoint 28, which is to be measured or marked out with the aid of theauxiliary measuring instrument 40. The end 43 is configured in theexample as a contact tip, with which a respective point 28 is designatedby being touched. As an alternative, such a point 28 is designatedcontactlessly, for example in that at the end 43 there emerges thevisible light of a laser distance meter, with which the point 28 can bemarked in a punctiform manner and measures the distance between theauxiliary measuring instrument 40 or an auxiliary-measuring-instrumentreference point and the point 28. As a further option, the contact fordesignating the point 28 is not arranged on the longitudinal axis 48,but at a distance from it at a defined angle, for example at rightangles, so that the tip or the end 43 is L-shaped. Such a configurationmay be advantageous in the case of certain surveying tasks, for exampleto contact and survey a point on the inner periphery of a pipe, conduitor hole.

In the case depicted, the distance between the reference point and thepoint 28 to be surveyed or marked out is already known on account of thefixed length L of the main body 42 or the auxiliary measuring instrument40 and does not have to be separately measured for the determination ofthe position of the point 28. The position and orientation of theauxiliary measuring instrument 40 are in any case measured during thedesignation of the point 28 by a surveying device stationed at adistance, so that the absolute position of the point 28 can beascertained on the basis of a known, absolute position of the surveyingdevice, the position and orientation of the auxiliary measuringinstrument 40 and the length L or the distance between the auxiliarymeasuring instrument 40 and the point 28.

In the example, as a measuring aid for determining the position andorientation of the auxiliary measuring instrument 40, there is a sphereattachment 41 at the “upper” end of the measuring pen 40. This sphereattachment 41 has on its surface a code which can be evaluated in acamera image (recorded by the surveying device) in such a way that theorientation of the sphere 41 in relation to the image or the camera (orthe surveying device) can be determined. On the basis of the depictedsize of the sphere 41 and/or the code and/or a further code, the rangebetween the camera and the sphere 41 is also determined, from which,together with a measured or known recording direction (and if applicableposition of the sphere or of the center of the sphere in the image), theposition of the sphere can be determined (also see the description ofFIG. 1).

The auxiliary measuring instrument 40 therefore has at least one body bymeans of which the orientation and/or position of the auxiliarymeasuring instrument 40 can be determined in interaction with anexternal surveying device, with which the auxiliary measuring instrument40 forms a surveying system. Optionally, the pen 40 has a supportinginertial measuring unit (IMU), in order to make the locationdetermination more robust or to bridge dead angles, in which locationdetermination is not possible on the basis of the sphere 41 because theline of sight is interrupted. Also, such an IMU can be used incombination with position tracking on the basis of theposition-indicating body 41, i.e. when there is a position-changingmovement of the pen 40, a comparison of the IMU data with the positiondata that are obtained by the surveying device on the basis of the body41 is performed.

As an alternative to the sphere body 41 that is shown, which allows bothposition determination and orientation determination, an auxiliarymeasuring pen 40 according to the disclosure has a body which allows theposition determination with the surveying device, and the orientation isdetermined by means of internal sensors in the pen.

The auxiliary measuring pen 40 additionally has a man-machine interface,which in the example has a display 44, a scroll wheel 47 and a button45. The display serves for displaying user information and is optionallytouch-sensitive, in order to allow user inputs. As an alternative or inaddition, the scroll wheel 47 serves for user input. The button 45,arranged separately on the main body 42 and also of an enlarged form,likewise serves for user input or control, wherein it serves especiallyfor triggering the position determination of the point 28. Once the userhas placed the pen 40 on the point 28 in a way suitable for surveying,the user initiates a command to the controller of the surveying systemby means of the button, so that the position determination takes place.

The auxiliary measuring instrument 40 or the surveying system isoptionally designed to prompt the user during a measuring task, forexample to indicate the next action steps or in that a system controllergives instructions to the user via the display 44 in dependence on acontinuously ascertained position and orientation of the pen 40, andconsequently of the user. As a further optional feature, in the examplethe auxiliary measuring instrument 40 has a rule 46, with which lengthson the surveying site can be handily measured. In the example, this isdesigned such that it can be folded out (indicated in the drawing by thearrow 46 a).

FIG. 8b shows an example of surveying an object point 28 with the aid ofthe auxiliary measuring pen 40. The pen 40 is ergonomically designed,for example by means of a gripping region for at least the thumb andindex finger, and also in particular the middle finger, of a user, insuch a way that—like a customary pen—it can be used by the user 29 in aone-handed manner, as shown. In order for example to survey a point ofan object 49 in a terrain, for example outdoors or inside a building, asurveying device 30, for example a total station, is positioned in aknown way, so that the device 30 can be aligned with the auxiliarymeasuring instrument 40. The surveying device has a camera 31 that canbe pivoted about two axes y, z.

The camera aligned with the auxiliary measuring instrument 40, or to bemore precise with its sphere attachment 41, records at least one imageof the sphere attachment 41 when the auxiliary measuring instrument 40designates the terrain point 28, that is to say in the example the user29 uses his hand to bring the pen 40 onto the point 28, so that the tipof the pen touches the object point 28. By means of image evaluation ofthe camera image of the sphere attachment 41, the position andorientation of the pen 40 are ascertained. Starting from the knownposition and alignment of the surveying device 30, the position of thepoint 28 is ascertained by means of knowledge of the range or positionof the auxiliary measuring instrument 40 and its alignment and also thelength of the measuring pen 40 (or distance between an internalreference point of the pen 40 and the object point 28).

Here, the tip 43 is optionally designed as a probe which, when it makescontact with or touches the terrain point 28, automatically triggers theposition determination or the recording of a camera image of the sphereattachment 41, wherein a corresponding command is output by theauxiliary measuring instrument 40 to a controller of the surveyingdevice 30, for example by means of a Bluetooth connection.

As an alternative or in addition, when it is touched, the probeautomatically triggers a measurement. As a further option, automatictriggering of a measurement or of a working operation takes place assoon as the pen 40 has assumed a desired position.

Instead of such a surveying operation, alternatively a desired positionon the object 49 is marked by means of the pen, for example in that thetip of the pen is designed as a pen marker, for example in the manner ofa felt pen or crayon. Consequently, the measuring pen 40 can also servefor staking out points.

The handy design of the auxiliary measuring instrument 40 in the mannerof a pen, which can be easily used with one hand (for which purpose forexample the center of gravity of the pen 40 is also situated in such away that it allows it to be handled with one hand reliably and at leastlargely without fatigue), offers the advantage of much less laborioushandling than conventional auxiliary measuring instruments of thegeneric type. Moreover, it also allows the marking of terrain pointsthat cannot be reached for example with plumbing poles of the prior art,either because the plumbing pole cannot be positioned perpendicularly onthe point as required or because the plumbing pole is too long. Bycontrast, with the present auxiliary measuring pen 40, on account of theascertainment of all six of its degrees of freedom, contact can be madein any alignment and, on account of its handy, comparatively small size,even concealed points can be surveyed/marked out. Consequently,surveying operations in the near field or in confined spaces such ascorners, casings, wall recesses, bay windows, in furniture etc. are alsomade possible.

FIG. 8c shows in cross section a further exemplary embodiment of ameasuring pen 40. The pen 40 has at its upper end a body 41, in theexample configured as a polyhedron. The body 41 is the bearer of a code,which, as previously described, allows image-based determination of thelocation of the pen 40 by means of an external camera. Inside the body41 there is a printed circuit board 43 d, which in the example is thebearer of an inertial measuring unit (IMU) 43 f. The IMU 43 f serves forsupporting the location determination, for example in order to make thelocation determination more robust or to bridge dead angles, in whichlocation determination is not possible on the basis of the optical code,for example because the line of sight to the camera is interrupted.Furthermore, the printed circuit board 43 d bears a communicationsmodule, for example in the form of an IRDA module. Moreover, insidethere are four lighting means (LEDs) 43 e (two on top and two underneathon the board 43 d), whereby the body 41 is designed as a luminaire. Theillumination is for example variable, for example in order to indicatethe respectively applicable operating state of the pen 40 for example bymeans of different colors.

Apart from a battery 43 b, the pen 40 has at its lower end 43 a probeball 43 a. In the example, the ball can be laterally deflected, so thatlateral probing of objects is made possible. When there is such a probeball 43 a, the pen 40 is optionally additionally provided withelectronic and/or mechanical correction of the extent of the ball, sothat during the ascertainment of the point 28 the size of the ball isautomatically taken into account in a corrective manner. In the example,the deflection of the probe ball 43 a is measured by means of magnets 43g coupled to the probe ball 43 a, which are detected by a Hall element43 h. As an alternative, a piezo element serves for determining thedeflection.

FIG. 8d shows a further embodiment of a pen 40 with a probe ball 43 a.The probe ball 43 a is arranged by means of a ball joint 43 i in a mount44 j in the lower end 43 of the pen 40 in such a way that, during ameasurement of a point of an object 49, the ball 43 a is deflectedexactly by the radius R of the ball. There is consequently a correctionof the extent R of the ball 43 a, in that a measured-value recording ofan object point takes place precisely when the deflection caused by theprobing of the object 49 corresponds to the ball radius R. This isensured by the mechanical arrangement of the probe ball 43 a.

FIG. 9a shows a further embodiment of a pen-like auxiliary measuringinstrument 40. In the example, the auxiliary measuring instrument 40 hasan exchangeable tip 43. This can be fitted on the main body 42 of thepen 40 by means of a holder 50 and removed again. In this way, varioustypes of ends or tips 43 can be advantageously used, so that thefunctional scope of the auxiliary measuring instrument 40 can beextended in comparison with a fixed tip. For example, a purely markingtip, such as for example a felt pen tip, can be exchanged for a sensortip, or a tool tip can be fitted. Also possible of course as an optionare embodiments with more than one tip or more than one tool or sensor,which may be exchangeable or fitted in a fixed manner.

FIGS. 9b-9d show three examples of possible tip models. FIG. 9b shows atip that is designed as a line laser 52. This allows laser lines to beindicated by means of the pen 40, for example on the wall of a buildingin the course of construction work.

FIG. 9c shows a further example of a tool tip. This is designed in theexample as a spray tip 54, so that paint from a tank 55 can be appliedby means of the pen 40, for example to the wall of a building, forexample in order to mark layout geometries.

FIG. 9d shows a metal detector 53 as an example of a sensor tip, so thatmetals can be detected with the auxiliary measuring instrument 40.

The button 45 shown in FIG. 9a is optionally provided in the case of anactive tip, such as for example one of the tips 52, 53 or 54, in orderto trigger the respective function of the tip. For example, therefore,by actuating the button 45, a spraying operation with the spray tip 54is triggered or the metal detector 53 is activated.

As a further option, shown in FIG. 9a , the holder 50 has a means 51 bywhich the respectively attached tip can be automatically identified. Forexample, as shown, there are electrical contacts 51, which have acorresponding counterpart on the tip 43 that identifies the respectivetip 43, for example an ID chip. As a further example, the identificationis performed optically by means of, in that for example an opticalcoding, such as for example a barcode, which is provided on therespective tip in the holding region, can be read by means of an opticalunit 51. In the course of the identification, a transmission of thesize/length of the tip takes place, so that the actual length of the penis automatically taken into account during the ascertainment of themeasurement results.

As a further option that is not shown, the holder 50 is provided inorder to be able to receive extension pieces. Therefore, extension partscan be exchangeably fitted between the main body 42 and the tip 43, sothat the length of the pen 40 is variable. This allows for example thelength of the pen 40 to be adapted to different measuring tasks, forexample increased in order to reach points in a relatively deepdepression. As an alternative to such extension pieces that can befitted, the length of the instrument 40 or its body 42 may be variablydesigned, in that the main body 42 is designed as a kind of telescopicpole. The tip 43 is consequently then retractable and extendable,particularly advantageously in a stepless manner. This may for examplebe performed by the user, in that the user turns the wheel 47 a.

FIG. 9e shows a further example of a tip. This tip 56 has a measuringtape 57, which is secured in such a way that it can be wound up in areceiving container 59 attached to the tip 56. The receiving container59 is either fixedly attached to the tip 56 or—in particular in the caseof a non-exchangeable pen tip—removably fitted on the tip 56. The lengthof the measuring tape 57 is therefore variable, wherein the container 59has an arresting mechanism (not shown), with which a chosen length ofthe measuring tape 57 can be set. The measuring tape 57 serves forexample for manually measuring out distances from the point 28 contactedby the tip to a point in its vicinity. As an alternative or in addition,the end of the measuring tape 57 has, as shown, a marking means or aholder for such a marking means, so that for example, as shown, a pencil58 a can be connected to the measuring tape 57, and consequently the tip56. Once the measuring tape 57 has been arrested, for example a circleor an arc of a circle 58 can therefore be drawn by the user, for exampleon a wall of a building, wherein the center point of the circle thenlies on the longitudinal axis 48 (see FIG. 4a ). Such marking out of acircle serves for example for marking a circular area in which aspecific manual construction activity is intended to take place.

FIG. 10 shows a first example of a laser receiver 1, which is designedfor providing a physical, permanent marking 5 on a surface of a building12. The laser receiver 1 has a housing 7 with a front surface 9 and arear surface (not shown). The front surface 9 has a line detector 6,with which laser light 3 can be captured. The laser light 3 is emittedby a construction laser 11, for example a rotation laser, and representsin a known way a position reference, for example in the form of areference plane 13, as shown. A position of the receiver 1 in relationto the position reference is inferred from the point of incidence of thelaser light 3 on the detector 6 by means of a controller of the laserreceiver 1 (not shown). In the example, the vertical position of thereceiver 1 can consequently be ascertained (at least as long as thedetector 6 is moving within the reference light 13). As an alternativeto the representation shown, the detector is of a flat design, so thatit is additionally possible to infer an orientation (rotation) of thereceiver about the axis perpendicular to the surface of the building 12.

The laser receiver 1 also has a handheld continuation 8 in the form of astick. Moreover, the rear surface of the housing 7 is of a planar designin such a way that, by manually gripping the stick 8, a user 2 candisplace the housing 7 or the laser receiver 1 along the surface of thebuilding 12, wherein the receiver 1 strictly follows the profile of thesurface of the building 12. To put it another way, the receiver 1 isdesigned in such a way that it can be manually guided in close contactwith the surface of the building 12 over a large area. As an alternativeto the embodiment shown, the housing 7 itself is shaped such that it canbe held by a hand, for example by corresponding ergonomic indentations,and does not have a stick. Such a less bulky embodiment is particularlyadvantageous for small-scale marking tasks, whereas the embodiment shownwith a stick 8 offers particular advantages for applications over largerareas.

The laser receiver 1 also has a marker (not shown), which is designedfor example as an inkjet printer or laser inscriber, so that, in thestate in which it is placed against the surface of the building 12, itcan print onto or burn into the surface. In the case of a printer, it iseither a single-color printer or a multi-color printer, wherein specialinks or media, such as for example fluorescent paint or clear varnish,can optionally also be used for preserving/sealing an applied marking.Advantageously, the printer is designed also to be able to print onceilings, that is to say against gravitational force. The marker mayalternatively be designed for mechanical marking, for example as acenter punch.

Furthermore, the laser receiver 1 has a memory (not shown), in which aplanned position, for example as part of a plan of a building, is storedin a retrievable manner. Such a planned position is for example alocation on the surface of a building 12, at which a hole is to bedrilled or some other installation measure is to be performed. Thememory may also be a volatile memory for only providing the positiondata for a short time. Then there is for example a cableless datatransmission (by Wi-Fi or Bluetooth etc.) of the position data in realtime from an external device (on the construction site or elsewhere, forexample in a cloud), where the position data is stored in a permanentmemory. A data transmission from an external device is optionally alsoused for example in order to output further information or controlcommands to the printer, for example with respect to the selection ofthe printing ink to be used.

This planned position is then physically and permanently markedpositionally accurately on the surface of the building 12 with the aidof the laser receiver 1 (as a difference for example from a marking bymeans of light, which is not of a physical nature and ceases when thelight emitter is removed (where “permanently” also includes that themarking 5 disappears after a certain period of time, for example in thatit has been applied with a UV-sensitive paint, which by definition fadesover time). For this purpose, the controller of the laser receiver 1 isdesigned in such a way that it is sufficient just to guide the receiver1 or the housing 7 or the marker approximately over the plannedlocation. The user 1 therefore displaces the receiver 1 over the surfaceof the building 12 by means of the stick 8 without having to knowexactly where on the surface 12 a marking is to be provided. This taskis undertaken by the controller, which retrieves the planned positionand continuously compares the position of the laser receiver 1 given onthe basis of the position reference with the planned position, in orderwhen the planned position is reached or passed over to give a command tothe marker to print a marking 5 at the planned position.

In other words, with a random, or at least not exactly targeted,movement 10, the user 2 passes the receiver over a certain surface area,somewhere within which the planned location is located, and as soon asthe planned location is passed over “by chance” in the course of themovement 10, or as soon as the planned location is within a marking zoneor printing area of the laser receiver 1 (that is to say “can bereached” by the marker), the controller triggers the marking operationon the basis of the position reference given by the laser beam. In thepresent example, it is expedient to use a visible laser beam 3, so thatthe user 2 only has to displace the receiver 1 along the laser line 13that is visible on the surface of the building 12.

In the example, the laser receiver 1 is also designed to print furtherinformation onto the surface of the building 12 in addition to the(position) marking 5, for example a text 4 describing the marking 5and/or additional graphics, so that for example working instructionsbased on the marking 5 are available directly at the installation site.

Since, for example, only a horizontal position reference is generallygiven by the light 3, but for a positionally accurate marking there mustalso be at least information on the position in the vertical direction,for example a second reference plane in the vertical direction iscreated by a second reference light, so that the planned position can bemarked on the basis of the crossing point of the two reference planes.As an alternative or in addition, the laser receiver 1 has one or moreposition encoders (see the following figures), with which furtherdegrees of freedom can be determined, so that the automatic positionallyaccurate marking is made possible.

FIG. 11 shows an example of a laser receiver or construction-siteprinter that has a position encoder. The rear surface 16 of the housingis shown, having a linear printing area 15 and two position encoders 17.

The printing line 15, for example a row of inkjet nozzles, allowsprinting over a surface area. Moreover, by contrast with a punctiformprinting area, a greater printing width Y is available, so that, forexample for providing a punctiform marking, it is sufficient to passover the planned location somewhere on the width Y, to allow thislocation to be marked. That is to say that the “tolerance” of the atleast partially undirected or untargeted manual displacement isincreased. In a practical respect, there is a considered compromisebetween as large a printing area as possible and the handiness and/orproduction costs of the printer.

The position encoders 17 are designed in the example as optical ormechanical position encoders (as known for example from computer mousedevices), whereby a relative displacement covered by the laser receiver(and if applicable also the extent of a rotational movement) along thesurface of the building can be measured. By means of such a measurementof the displacement in the manner of dead reckoning, for example thehorizontal position of the printer or laser receiver can be continuouslydetermined on the basis of a known location. For example, the edge ofthe building 14 (see FIG. 10) serves as such a defined starting point inthe horizontal direction, so that the user 2 places the receiver 1against this edge 14 and from there passes it over the wall 12 in theplane 13.

In the example, the rear surface also has at the corners four probingelements or guiding elements 19, designed as rollers or balls. Thesemake it easier for the housing to be precisely displaced so as to followthe profile of a surface of a building. As an alternative or in additionto the rollers or balls 19, for this purpose the housing has rolls.

Since, with such a position encoder 17, a vertical distance can also bemeasured, the position data of the position encoder 17 are optionallyused to increase the robustness of the position referencing by means ofthe position-reference laser light. For example this is used forbridging areas within which a position referencing is not possible onthe basis of the laser light, for example since the laser beam cannotreach all of the surface of the building concerned because of anobstacle. Therefore, shaded locations can nevertheless then be markedpositionally accurately.

FIG. 12 shows an alternative embodiment of a position encoder. The frontside 6 of the receiver or printer housing is shown. Apart from the laserdetector line 6, the front side has three lighting means 18, for exampledesigned as LEDs, which are arranged in a defined manner on the frontside. These LEDs are recorded as points of light by an external camera,such as for example surveying devices of the prior art have. Since thearrangement of the LEDs is known to the surveying device, the spatialorientation of the housing can be inferred from the image of the LEDs ina way known per se. As an option, the position encoder is designed insuch a way that it is possible to dispense with position referencing bymeans of laser light or the presence of a laser detector, i.e. in anembodiment as an alternative to the representation shown all of thenecessary position and/or orientation information is ascertained andprovided throughout by the position encoder.

In the case given by way of example that the receiver is strictly guidedon the surface of the building, which for marking a horizontal surfacearea can also be ensured for example by a cardan suspension (i.e. it ismechanically ensured that the printer is aligned perpendicularlythroughout), the movement is consequently restricted to the plane of thesurface area, i.e. it is already known or predetermined apart from twotranslational variables and one rotational variable. Consequently, insuch a case it is sufficient for there to be one position encoder, whichdetermines the movement with respect to these three degrees of freedomor, in the case of position referencing in the vertical direction on thebasis of the detected laser light, also only with respect to onetranslational (horizontal) degree of freedom and one rotational degreeof freedom (rotation of the housing in the planes of the surface area).The normal to the plane/surface area can in this case be determined forexample by means of the trajectory of the printer movement on thesurface area. For example, the position encoder then has an inclinationsensor and a yaw-angle sensor.

If there is no such restriction or partial predetermination of themovement because the construction-site printer is not moved along on thesurface of the building (in close proximity to it), the positionencoders or encoder are preferably designed for determination with sixdegrees of freedom. For example, the lighting means 18 are thereforeselected in number and arrangement in such a way that the location andorientation of the receiver or printer can be determined with them (bymeans of an external measuring device) with respect to all six degreesof freedom. Here, too, an alternative option is to dispense withposition referencing by means of laser light or the presence of a laserdetector.

As an alternative to a handheld marker, it has a drive and is designedas an autonomous or semiautonomous vehicle (ground-based, UGV orair-based, UAV). In such embodiments, a determination with six degreesof freedom is particularly advantageous, in order for it to be possibleto dispense with a strict guidance of the device along the surface ofthe building, but for example the distance from the surface or thealignment about all three axes of rotation may also be variable—at leastwithin certain limits.

FIGS. 13a-13c illustrate a method for marking points on an object on thebasis of planned positions for purposes of constructional activities.Shown is a stationary surveying device 90, which has a base 91 and antargeting unit 92 arranged on the base 91. The targeting unit 92 isrotatable with respect to the base 91 about two axes z and y and isdesigned for the emission of a laser beam as a free beam 94 in a targetdirection x onto the object, which in the example is an interior room.The respectively applicable target direction is measured for example bytwo angle meters for the respective axis z, y. The measuring and markingdevice 90 serves for the measuring-based capture and marking of points95a-95d in three-dimensional space. With the measuring and markingdevice, lines over a distance, in particular distances, surface areasand formed by a number of surface areas can be surveyed.

Object points or their associated positions can be ascertained in polarcoordinates from the measured values supplied for the two solid anglesfrom the axes z and y and the range reported by a laser distance meterof the surveying device 90 in a controller of the device 90 withsingle-point evaluating functionality and stored at least for a certaintime. In a known way, a distance can be calculated from two spatialpoints 95 a, 95 b and a surface area can be calculated from threespatial points 95 a, 95 b, 95 c. In this way, a space formed by a numberof surface areas or walls can be recorded, surveyed and stored as aspatial model.

With the surveying device 90, in the reverse way, marking points can beprojected with any desired repeating accuracy within the measuringresolution onto a surface area, for example one of the walls shown. Whenit is incident on the surface area, the optically visible laser beam 94generates a visible point of light. A permanent marking can then beprovided at this location manually or by means of a self-marking laserreceiver or construction-site printer explained above.

The position or the coordinates of the required marking points arestored in a device memory or are calculated by the controller. For this,the required position data are input or recorded, for example manuallyor by means of an interface. These data may be for example distances tobe removed or angles from such reference lines or points of the surfacearea or of the space. To go to a stored or calculated position or objectpoint be marked, the aiming direction x is changed manually orautomatically until the deviation from the desired alignment calculatedon the basis of the data is equal to zero, also taking into account hereif applicable the distance from the surface area measured by measuringbeam 94. In the example, the controller is capable of carrying outcalculations with the measured spatial points 95 a-95 d and athree-dimensional depiction of the surrounding space.

Instead of a laser beam 94, the marking beam may also consist of someother optically visible light beam or the like. It is also possible tomake the marking beam only visible by surface reactions when it isincident on an object. The measuring beam does not have to be opticallyvisible per se. Rather, the range of a spatial point 95 a-95 d may bemeasured in any way desired, allowing an additional optical device to beused for aiming at the spatial point 95 a-95 d.

The object points 95 a-95 d to be marked for purposes of constructionalactivities are for example a series of drilled holes in the walls, theceiling or the floor. These drilled holes therefore represent thedesired marking points 95 a-95 d. The (desired) positions of the desireddrilled holes are stored in a retrievable manner in the memory of thesurveying device 90. The actual dimensions of the space, which arerequired for ordering the system, are provided for example by surveyingwith the surveying device 90 itself in the course of, or in directpreparation for, the marking activity, but may alternatively also beprovided on the basis of a digital plan of the building or model of thebuilding and/or a previous survey at a time longer ago.

For this purpose, the surveying device 90 is as far as possiblepositioned in the middle of the space to be surveyed in such a way thatall of the points to be measured or marked can be reached by the laserbeam 94. It must also be ensured per se during the entire measuring andmarking operation that the measuring and marking device 90 does notchange its positioning P1 in the space, i.e. the reference location P1.

However, this ideal situation does not always exist or can beestablished, for example because not all of the required measuring ormarking points can be aimed at by a single positioning, it beingpossible that the positioning is chosen unfavorably by the user or,depending on the measuring environment, no positioning that satisfiesthese conditions can be found in the first place. For example, as shownin FIG. 13a , the point 95 d cannot be surveyed or marked from the firstpositioning P1, since the obstacle, the pillar 96, is in targetdirection x, and consequently covers the measuring beam 94.

Therefore, once the points 95 a-95 c that can be reached from the firstpositioning P1 have been surveyed or marked, it is ascertained whetherand which object points have not yet been surveyed or marked. In theexample, it is therefore established for example that the point 95 d hasnot yet been marked or cannot be marked from the first positioning P1(see FIG. 13a ). A relocation of the surveying device 90 is necessary inorder to be able to mark the missing object point 95 d. In preparationfor this, a first depiction of the surrounding area is produced with acamera of the surveying device 90, that is to say a camera image atleast of part of the space is recorded. As an alternative, such adepiction of the surrounding area may for example also be produced bymeans of a laser scan.

Then, the surveying device 90 is changed over from the first positioningP1 to a second positioning P2 (see FIG. 13b ). In order then, in spiteof the changed reference location and without having to carry outlaborious manual position referencing known from the prior art, afurther depiction of the surrounding area is automatically produced fromthe second positioning P2, that is to say for example a second cameraimage is recorded. In this second camera image, the already capturedpoints 95 a-95 c are automatically detected by the controller by imageevaluating methods known per se on the basis of the first camera image.Since their positions are known and stored in the memory, thecoordinates of the second positioning P2 can be inferred from this byautomatic surveying from the second positioning P2, as indicated in FIG.13b . The second positioning is consequently positionally determined onthe basis of the known first positioning P1.

Then, as shown in FIG. 13c , the point 95 d on the building that isstill missing and can be aimed at from the second positioning P2 ismarked from the then known positioning P2. The automaticself-determination of the new positioning P2 by the surveying device 90therefore advantageously allows a simple method by which covered objectpoints can be surveyed or marked. As an alternative or in addition tothe aforementioned determination of the second positioning P2 on thebasis of a comparison with the first camera image recorded from thefirst positioning, a comparison of the second depiction of thesurrounding area with a stored digital plan of the building or room,which for example as mentioned above has been produced by means ofmeasurements from the first positioning P1, is performed to determinethe second positioning P2. As an alternative or in addition, thedetermination of the second position is performed by means ofstructure-from-motion algorithms known per se, on the basis of data ofan IMU and/or camera data.

Optionally, before the relocation of the surveying device 90, a proposalfor the second positioning P2 is output on a display as an instructionfor the user by the controller of the surveying device 90. Thecontroller therefore determines for example on the basis of the knownpositioning P1 or on the basis of a plan of the building or room and thestored position of the still missing object point 95 d, or the targetdirection x based on it, which positioning or which positioning area inthe room comes into question or is optionally suited for surveying ormarking the missing object point or points, for example with respect tothe range from an object point or a number of/all of the missing objectpoints.

Regarded for example as optimally suited is a location of which theangle of incidence of the laser beam 94 on locations to be surveyed orto be marked is incident with a cross section that is distorted aslittle as possible. Shallow angles of incidence of the beam areunfavorable, for which reason positionings that lead to such shallowincidence are ruled out, and instead one or more positionings areascertained that allow the incidence of the laser beam 94 to be asperpendicular as possible for one or more object points still to besurveyed or to be marked.

This instruction or this positioning proposal is preferably displayed tothe user in a graphic form on a device display, for example embedded ina 2D or 3D representation of the room or a plan of the building or room.

It is obvious that these illustrated figures only schematicallyrepresent possible exemplary embodiments. The various approaches canalso be combined according to the invention with one another and withsurveying devices and surveying methods of the prior art.

What is claimed is:
 1. A method for surveying and/or marking points onan object on the basis of planned positions for purposes ofconstructional activities, with the steps of setting up a stationarysurveying device at a first known positioning in a surrounding area ofthe object, wherein the surveying device has a base, a targeting unit,in particular a telescopic sight, which defines a target direction (x)and can be pivoted with respect to the base about at least one axis (y,z), in particular two axes orthogonal to one another, a beam source, inparticular a laser source, for generating radiation and also an opticalunit for emitting the radiation as a free beam in the target direction,wherein the free beam serves for surveying and/or marking object points,at least one angle meter and also an angle-measuring functionality formeasuring the target direction (x), and a controller with single-pointdetermining functionality, a memory, in which input or surveyedpositions can be stored, in particular as part of a plan of a buildingor room, retrieving from the memory a set of object points of the objectto be surveyed and/or to be marked, surveying and/or marking from thefirst positioning (P1) object points of the set of object points thatcan be surveyed and/or can be marked from the first positioning (P1) bymeans of the free beam, on the basis of the target direction (x),ascertaining missing object points of the set of object points,relocating the surveying device to a second, unknown positioning (P2) inthe surrounding area of the object, automatically determining the secondpositioning (P2) by the surveying device on the basis of the knowledgeof the first positioning (P1), so that the second positioning (P2) isknown, surveying and/or marking missing object points by means of thefree beam from the second positioning (P2).
 2. The method as claimed inclaim 1, wherein before the relocation, a positioning proposal suitablefor the second positioning (P2) is at least approximately calculated bythe controller of the surveying device, on the basis of storedpositions, and the positioning proposal is displayed to a user on adisplay.
 3. The method as claimed in claim 2, wherein a measuring angleas perpendicular as possible of the free beam in the case of one or moremissing object points is used as a criterion for the calculation of thepositioning proposal.
 4. The method as claimed in claim 2, wherein thecalculation of the positioning proposal takes into account informationconcerning a target direction (x) in relation to at least one of themissing positions.
 5. The method as claimed in claim 2, wherein thedisplay of the positioning proposal takes place in a graphic form,embedded in a visualization of a plan of a building or room and/orembedded in a 2D or 3D panoramic image, recorded in situ, of thesurrounding area and/or as an augmented reality representation in a livevideo image of the surrounding area.
 6. The method as claimed in claim1, wherein the automatic determination of the second positioning (P2) isperformed on the basis of a depiction of the surrounding area producedby the surveying device in the second positioning (P2), in particularwherein the depiction of the surrounding area is produced by means of acamera image of the surveying device and/or a laser scan carried out bymeans of the free beam.
 7. The method as claimed in claim 6, wherein: inthe course of the automatic determination of the second positioning(P2), the depiction of the surrounding area of the second positioning iscompared with a depiction of the surrounding area produced in the firstpositioning (P1), in particular wherein positions that can be seen inboth depictions of the surrounding area and are processed from the firstpositioning (P1) serve as a position reference and/or is compared with astored digital plan of a building or room.
 8. The method as claimed inclaim 1, wherein the automatic determination of the second positioning(P2) is performed by means of a structure-from-motion algorithm on thebasis of measurement data of an inertial measurement unit and/or aseries of camera images.
 9. A stationary surveying device for surveyingand/or optically marking points on an object on the basis of plannedpositions for purposes of constructional activities, wherein thesurveying device has a base, a targeting unit, in particular atelescopic sight, which defines a target direction (x) and can bepivoted with respect to the base about at least one axis (y, z), inparticular two axes orthogonal to one another, a beam source, inparticular a laser source, for generating radiation and also an opticalunit for emitting the radiation as a free beam in the target direction(x), at least one angle meter and also an angle-measuring functionalityfor measuring the target direction (x), and a controller withsingle-point determining functionality, a memory, in which input orsurveyed positions can be stored, in particular as part of a plan of abuilding or room, wherein: the controller is designed for performing themethod as claimed in claim
 1. 10. A computer program product withprogram code, which is stored on a machine-readable carrier, forperforming the method as claimed in claim
 1. 11. The method as claimedin claim 3, wherein the calculation of the positioning proposal takesinto account information concerning a target direction (x) in relationto at least one of the missing positions.
 12. The method as claimed inclaim 3, wherein the display of the positioning proposal takes place ina graphic form, embedded in a visualization of a plan of a building orroom and/or embedded in a 2D or 3D panoramic image, recorded in situ, ofthe surrounding area and/or as an augmented reality representation in alive video image of the surrounding area.
 13. The method as claimed inclaim 4, wherein the display of the positioning proposal takes place ina graphic form, embedded in a visualization of a plan of a building orroom and/or embedded in a 2D or 3D panoramic image, recorded in situ, ofthe surrounding area and/or as an augmented reality representation in alive video image of the surrounding area.
 14. The method as claimed inclaim 5, wherein the automatic determination of the second positioning(P2) is performed on the basis of a depiction of the surrounding areaproduced by the surveying device in the second positioning (P2), inparticular wherein the depiction of the surrounding area is produced bymeans of a camera image of the surveying device and/or a laser scancarried out by means of the free beam.
 15. The method as claimed inclaim 7, wherein the automatic determination of the second positioning(P2) is performed by means of a structure-from-motion algorithm on thebasis of measurement data of an inertial measurement unit and/or aseries of camera images.
 16. A stationary surveying device for surveyingand/or optically marking points on an object on the basis of plannedpositions for purposes of constructional activities, wherein thesurveying device has a base, a targeting unit, in particular atelescopic sight, which defines a target direction (x) and can bepivoted with respect to the base about at least one axis (y, z), inparticular two axes orthogonal to one another, a beam source, inparticular a laser source, for generating radiation and also an opticalunit for emitting the radiation as a free beam in the target direction(x), at least one angle meter and also an angle-measuring functionalityfor measuring the target direction (x), and a controller withsingle-point determining functionality, a memory, in which input orsurveyed positions can be stored, in particular as part of a plan of abuilding or room, wherein: the controller is designed for performing themethod as claimed in claim
 8. 17. A computer program product withprogram code, which is stored on a machine-readable carrier, forperforming the method as claimed in claim 8.